A conjugated diene polymer comprising a constitutional unit based on a conjugated diene and a constitutional unit based on a compound represented by Formula (1) below, R1Si(OR2)mR3nR4(3-m-n)  (1) wherein m represents 1 or 2; n represents 1 or 2; m+n=2 or 3; R1 represents a hydrocarbyl group having a polymerizable carbon-carbon double bond; R2 represents a hydrocarbyl group, and, when there are plural R2s, R2s each may be the same or different; R3 represents an aryl group that may have an oxygen-containing substituent, and, when there are plural R3s, R3s each may be the same or different; and R4 represents an alkyl group or a substituted amino group.